Influence of water level rise on currents and saltwater intrusion in the Changjiang Estuary

TANG Chuanmin; ZHU Jianrong

doi:10.3969/j.issn.1000-5641.201941001

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May 2020

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TANG Chuanmin, ZHU Jianrong. Influence of water level rise on currents and saltwater intrusion in the Changjiang Estuary[J]. Journal of East China Normal University (Natural Sciences), 2020, (3): 23-31. doi: 10.3969/j.issn.1000-5641.201941001

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TANG Chuanmin, ZHU Jianrong. Influence of water level rise on currents and saltwater intrusion in the Changjiang Estuary[J]. Journal of East China Normal University (Natural Sciences), 2020, (3): 23-31. doi: 10.3969/j.issn.1000-5641.201941001

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Influence of water level rise on currents and saltwater intrusion in the Changjiang Estuary

doi: 10.3969/j.issn.1000-5641.201941001

TANG Chuanmin,
ZHU Jianrong^,

State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai　200241, China

Received Date: 2019-01-08
Available Online: 2020-05-29
Publish Date: 2020-05-01

Abstract

Abstract

A semi-implicit estuarine, coastal, and ocean model (ECOM-si) was used to simulate and analyze the influence of a rise in water level on runoff, tidal and wind-driven currents, and on current and saltwater intrusion under the combined effects of various dynamic factors. In a scenario where the water level rises 30 cm in the Changjiang Estuary, numerical simulation results show that seaward runoff decreases due to augmentation of the river transection area; tidal currents decrease slightly with increases in water depth; the wind-driven current by northerly winds in the dry season is enhanced, which flow landward in the North Channel and seaward in the South Channel forming horizontal circulation; and the wind-driven current in the North Branch is strengthened. After the water level rise, saltwater intrusion in the North Branch is enhanced; salinity changes slightly in the middle reaches of the South Branch; the most distinct areas of saltwater intrusion enhancement are in the North Channel and North Passage, where the salinity rise is greater than 1 in neap tide and is somewhat reduced in spring tide; the salinity rise in the northern outlet of the North Channel reaches the maximum value observed in the entire estuary; and salinity on the shoal at the river mouth of the South Passage reduces because the water level rises and the nonlinear effect weakens. The water level rise, moreover, results in a salinity increase at the water intake of the three reservoirs (Qingcaosha, Chenhang, and Dongfengxisha) in the water source of the South Branch, which reduces water intake time and affects the safety of the water supply.
- Changjiang Estuary,
- water level rise,
- current,
- saltwater intrusion,
- numerical experiment

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References(16)

References

[1]	QIU C, ZHU J R, GU Y L. Impact of seasonal tide variation on saltwater on saltwater intrusion in the ChangJiang River Estuary [J]. Chinese Journal of Oceanology and Limnology, 2012, 30(2): 342-351. DOI: 10.1007/s00343-012-1115-x.
[2]	QIU C, ZHU J R. Influence of seasonal runoff regulation by the Three Gorges Reservoir on saltwater intrusion in the Changjiang River Estuary [J]. Continental Shelf Research, 2013, 71: 16-26. DOI: 10.1016/j.csr.2013.09.024.
[3]	LÜ H H, ZHU J R. Impact of the bottom drag coefficient on saltwater intrusion in the extremely shallow estuary [J]. Journal of Hydrology, 2018, 557: 838-850. DOI: 10.1016/j.jhydrol.2018.01.010.
[4]	LI L, ZHU J R, WU H. Impacts of wind stress on saltwater intrusion in the Yangtz Estuary [J]. Science China Earth Sciences, 2012, 55(7): 1179-1192.
[5]	LI L, ZHU J R, WU H, et al. Lateral saltwater intrusion in the North Channel of the Changjiang Estuary [J]. Estuaries & Coasts, 2014, 37(1): 36-55.
[6]	ZHU J R, WU H, LI L. Hydrodynamics of the Changjiang Estuary and Adjacent Seas [M]//Ecological Continuum from the Changjiang (Yangtze River) Watersheds to the East China Sea Continental Margin. [S.l.]: Springer International Publishing, 2015: 19-45.
[7]	杨桂山, 朱季文. 全球海平面上升对长江口盐水入侵的影响研究 [J]. 中国科学(B辑), 1993, 23(1): 69-76.
[8]	HANSEN N D, KOTERA A, SAKAMOTO T, et al. Sensitivity of salinity intrusion to sea level rise and river flow change in Vietnamese Mekong Delta impacts on availability of irrigation water for rice cropping [J]. Journal of Agricultural Meteorology, 2008, 64(3): 167-176. DOI: 10.2480/agrmet.64.3.4.
[9]	MACCREADY P, GEYER W R. Advances in estuarine physics [J]. Annual Review of Marine Science, 2010(2): 35-58.
[10]	BLUMBERG A F, MELLOR G L. A description of a three-dimensional coastal ocean circulation model [M]//Three-Dimensional Coastal Ocean Models. Washington, DC: American Geophysical Union (AGU), 2013: 1-16.
[11]	LI L, ZHU J R, WU H, et al. A numerical study on the water diversion ratio of the Changjiang Estuary during the dry season [J]. Chinese Journal of Oceanology and Limnology, 2010, 28(3): 700-712. DOI: 10.1007/s00343-010-9114-2.
[12]	朱建荣, 吴辉, 顾玉亮. 长江河口北支倒灌盐通量数值分析 [J]. 海洋学研究, 2011, 29(3): 1-7. DOI: 10.3969/j.issn.1001-909X.2011.03.002.
[13]	QIU C, ZHU J R. Assessing the influence of sea level rise on salt transport processes and estuarine circulation in the Changjiang River Estuary [J]. Journal of Coastal Research, 2015, 31(3): 661-670.
[14]	李永平, 秦曾灏, 段义宏. 上海地区海平面上升趋势的预测和研究 [J]. 地理学报, 1998, 53(5): 393-403. DOI: 10.3321/j.issn:0375-5444.1998.05.002.
[15]	WU H, ZHU J R. Advection scheme with 3rd high-order spatial interpolation at the middle temporal level and its application to saltwater intrusion in the Changjiang Estuary [J]. Ocean Modelling, 2010, 33: 33-51. DOI: 10.1016/j.ocemod.2009.12.001.
[16]	李路. 长江河口盐水入侵时空变化特征和机理 [D]. 上海: 华东师范大学, 2011.